Last Updated on December 23, 2025
Learn how industrial wastewater is treated before entering municipal systems. Understand screening, pH correction, grease removal, and Ontario bylaw compliance.
Industrial wastewater is treated through pre-screening, solid separation, oil and grease removal, pH correction, and filtration before it can enter municipal systems. Ontario facilities must meet local Sewer Use Bylaws that regulate contaminants, suspended solids, metals, and grease levels.
Why Industrial Wastewater Treatment Matters in Ontario
Industrial properties must treat water onsite to protect municipal sewers and the environment.
Local regulations such as Toronto Sewer Use Bylaw Chapter 681 and Peel Region Sewer Use Bylaw 53-2019 set strict discharge limits for contaminants.
1. Pre Screening and Solid Removal
The first step removes large debris from wastewater.
Common methods include:
- Bar screens
- Mesh strainers
- Sediment traps
This prevents solid waste from entering downstream equipment.
2. Oil and Grease Separation
Industries that use oils, lubricants, or food byproducts require interceptors, such as:
- Grease interceptors
- Oil and grit separators
- Dissolved air flotation units
These systems reduce floatables and protect municipal sewers.
3. pH Correction
Wastewater that is too acidic or alkaline cannot be discharged.
Facilities use:
- Neutralization tanks
- Controlled chemical dosing
- Mixing chambers
Ontario bylaws often require a discharge pH between 6.0 and 10.5 depending on the municipality.
4. Suspended Solid Removal
Processes that involve cutting, grinding, or food preparation release suspended solids into water.
Facilities reduce solids using:
- Settling tanks
- Clarifiers
- Filtration systems
- Centrifuges
Reducing solids helps protect pumps and main sewer lines.
5. Chemical or Biological Treatment
Some wastewater streams need additional treatment to remove contaminants.
Options include:
- Coagulation and flocculation
- Activated sludge systems
- Bioreactors
- Carbon filtration
These methods improve clarity and reduce organic loads.
6. Final Filtration and Sampling
Before discharge, wastewater goes through final filtration.
Most municipalities require:
- Flow monitoring
- Regular sampling
- Record keeping
- Inspections by municipal officials
Facilities must keep proof they are meeting local discharge limits.
Final Note
Industrial wastewater treatment is critical for safety, compliance, and environmental protection.
👉 Select Plumbing and Heating provides wastewater system installation, maintenance, and compliance support for facilities across the GTA.
FAQs
Q1: Do industrial facilities need their own wastewater treatment system?
Yes. Ontario regulations require pretreatment of industrial wastewater before discharge to municipal sewers.
Q2: What contaminants are restricted under Ontario sewer bylaws?
Oils, grease, metals, suspended solids, and chemicals above set limits are restricted.
Q3: How often should wastewater systems be maintained?
Maintenance depends on facility throughput, but most systems require monthly cleaning and yearly inspections.
Q4: What happens if a facility discharges untreated wastewater?
Violations can result in fines, equipment shutdowns, and legal action by the municipality.
